Protecting native tree diversity through more efficient conservation and restoration efforts is critical in Southeast Asia, where an increasing number of tree species face the threats of habitat loss, climate change, wildfires and other factors man-made. A new study published in the journal Biological conservation used a spatially explicit framework to identify species-specific priority areas for the conservation and restoration of endangered rosewood species in the Greater Mekong sub-region, an area that includes Cambodia, China, Laos, Myanmar, Thailand and Vietnam .
The researchers focused on three very valuable Asian rosewood (Dalbergia spp.) species – Siamese rosewood, Burmese blackwood, and Burmese rosewood – and found that all of these species faced significant risks to at least one of five threats in 75% of their native ranges: overexploitation, overgrazing, wildfires, habitat conversion and climate change. The continuing decline in genetic diversity reduces the ability of these trees to adapt and survive in a rapidly changing environment, narrowing the window of opportunity to restore highly fragmented productive populations due to human activity.
According to United Nations data, rosewood is the most profitable form of illegal flora trade, surpassing ivory in terms of commercial value. The risks they face from illegal logging and deforestation for agricultural expansion are compounded by other anthropogenic threats, such as climate change and forest fires.
To provide an overview of the diversity of environments in which these species grow and to assess current gaps for conservation measures, the researchers used a spatial framework that could complement field studies. “Spatial approaches serve as a complementary method to field studies, helping to narrow target areas for follow-up investigations and benefiting tropical regions where there is high species diversity and where conservation resources are limited.” explained study co-author Riina Jalonena, a researcher at the Alliance of Bioversity International and CIAT.
The analysis revealed that all three rosewood species were at risk across the Greater Mekong, particularly due to overexploitation, habitat conversion and fires. Unfortunately, only part of the rosewood population is found in protected areas, while the rest of the population is decreasing in areas not regulated by government bodies. However, even for species in protected areas, survival is not guaranteed due to limited access and rapid environmental changes.
Urgent conservation and restoration actions are needed to save these highly valued and threatened tree species. Scientists hope that, through regional initiatives guided by the action maps provided, transnational collaborations can be mobilized to safeguard these important resources and the ecosystems of which they are a crucial part.
Of Andrei Ionescu, Earth.com Staff Writer